Just curious if theres a way to really dig into a dns server to see if its bad or not (hosting adware / whatever). I have been digging through my logs and see something new everyday but I am curious how I can really dig into it to see what it really is.

I just want to know the best way to figure out if a DNS is bad. Say I keep on seeing foo.bar in my logs. I have to idea if it’s ad, malware or spam related. What’s the best way to go about digging through domains to see if they need to be added to a block list?